How Does an Excess Flow Check Valves Work?

Posted by AEPLGlobe on March 14th, 2018

Safety is one of the primary concerns in any industrial plant, commercial or residential space. And safety devices such as different types of valves are used in industrial units to manage the flow of liquids and gases. Excess Flow valves or EFVs are designed by excess flow check valve manufacturers for a variety of industrial requirements.

Purpose of Excess Flow Check Valves

As the name suggests, an excess flow check valve closes only when the force of the liquid or gas passing through the valve exceeds the power of the spring holding it open. Excess flow valves are mechanical safety devices installed inside natural gas service lines to control the flow of the liquids or gases.

Leading excess flow check valve manufacturers in India can design customised valves on the basis of client specifications. Some of the types of EFVs that can be utilised are screwed, flanged, internal and sandwich type valves.

How does an EFV work?

• If there is an EFV requirement, excess flow check valve manufacturers study the needs of the client and discuss the design with their teams. The EFV has to be customised for certain projects depending on the required pressure settings, end connections, material used and other parameters.
• Generally, the valve is placed under the ground with the service line. It is connected to a meter above the ground with pressure reading taken by service line technical experts.
• The body of the excess flow check valve is consists of a sleeve, keepers, spring, guide and poppet. Under normal conditions, the valve is kept open by the spring. But if there is a rupture in the service line carrying the gas, the pressure of the flow of the liquid or gas passing through the valve increases.
• Based on the functional output desired from the valve, the valve is set to close or trip if the spring experiences a pressure that exceeds the safety limit. The pressure of the spring can be noted on the meter connected to the spring.
• The valve opens up when the pressure level is restored to the safety limit that it was designed for.

So, the excess flow check valve ensures safety by stopping the flow of excess gas or liquid into the atmosphere and causing damage to life and property. But what needs to be noted is that, an excess flow check valve will not shut if there is a leakage or any rupture of the line at the customer’s side.

In India, excess flow check valves are widely used in residential complexes where there is a huge requirement for LPG supply to all the residences. Excess flow check valve manufacturers in India such as AEPL, study the layout of these housing complexes and their service lines. Based on their study, standard or custom-engineered EFVs are installed in the service lines for a controlled and safer supply of piped gas from the main gas line to residents.

Do you think EFV is an effective way for supply of petrochemical gases? Share your thoughts on the usage of EFVs.